Curved powered roller conveyor

ABSTRACT

A curved live roller conveyor is described in which a plurality of individual live rollers disposed at angles about the center of conveyor curvature are driven from a common powered drive shaft through a system of pulleys and elastomeric belts. Straight or tapered rollers are used, with pulley diameters being varied to provide constant rotational speed for each driven roller.

United States Patent Inventors Appl. No. Filed Patented Assignees CURVEDPOWERED ROLLER CONVEYOR References Cited UNITED STATES PATENTS 2,487,19611/1949 Sternad FOREIGN PATENTS 152,470 11/1955 Sweden PrimaryExaminer-Edward A1 Sroka Att0rney-Wolfe, Hubbard, Leydig, Voit & OsannABSTRACT: A curved live roller conveyor is described in which aplurality of individual live rollers disposed at angles about the centerof conveyor curvature are driven from a common powered drive shaftthrough a system of pulleys and elastomeric belts. Straight or taperedrollers are used, with pulley diameters being varied to provide constantrotational speed for each driven roller.

4 Claims, 5 Drawing Figs.

u.s. Cl 198/110, 198/127 Int. Cl ..B65g 13/02, 865g 21/12 Field ofSearch 198/34, 110,127,181-182 CURVED POWERED ROLLER CONVEYORDESCRIPTION OF THE INVENTION This invention relates to conveyors and inparticular to roller conveyors used to transport individual objectsalong a pass line. In its principal aspect the invention concerns a beltdrive for powering a plurality of individual conveyor rollers in acurved conveyor section.

A principal object of the present invention is to provide an improvedband or belt drive for the individual rollers of a curved live rollerconveyor It is further intended to provide a curved live roller conveyorsection in which the powered rollers each have the same rotational speedand peripheral speed, whereby a conveyed object will be rotated as ittraverses the curved section, whereby the object will exit the curvedsection in the same orientation as it entered.

A more detailed object is the provision of a drive for curved liveroller conveyor sections in which a plurality of angled live rollers maybe driven from a single straight drive shaft.

Other objects and advantages of the invention will become apparent fromreading the following detailed description in conjunction with thedrawings, in which:

FIG. I is a plan view of a curved portion of a live roller conveyorexemplifying the present invention;

FIG. 2 is a side elevation of the structure of FIG. 1;

FIG. 3 is a plan view of a second exemplary structure utilizing taperedrollers;

FIG. 4 is a side elevation of the structure of FIG. 3; and

FIG. 5 is an enlarged detail in perspective of the pulley and drive beltused in the foregoing exemplary embodiments of the invention.

While the invention is described in connection with certain illustrativepreferred embodiments, it will be understood that the invention is notrestricted to the particular uses and applications shown and describedherein, but on the contrary may be utilized in all conveyor driveapplications where a simple and reliable live roller drive is requiredfor curved conveyor sections.

Turning now to conveyor drawings, there is shown in FIG. 1 in simplifiedform an exemplary curved portion of a live roller conveyor in whichindividually powered transverse rollers are supported for rotation oncurved conveyor rails 11, and are each individually driven from a driveshaft 12 positioned adjacent the pass line of the conveyor. The passline is defined as the plane which includes the upper surfaces of therollers, and it will be seen that the individual rollers 10 are eachangled with respect to one another in the pass line plane. In theexemplary embodiments shown, the drive shaft 12 is disposed beneath thepass line a uniform distance from each of the live rollers 10. It willbe understood that nonpowered rollers (not shown) may be interposedbetween each of the live rollers 10 without departing from theinvention. The drive shaft 12 is powered for rotation by a motor 13.

As a principal feature of the invention, each of the powered liverollers 10 is individually driven at a uniform rotational speed by thedrive shaft 12, even though the angle between each roller 10 and thedrive shaft 12 is different from roller to roller. This is accomplishedthrough the use of a plurality of spool-shaped drive pulleys 16 carriedfor rotation by the drive shaft 12. Power is transferred from eachpulley 16 to its associated roller 10 through a resilient drivebelt 18,preferably of circular cross section such as an O-ring The belt ispreferably of a resilient elastomeric material so that it can stretchunder tension in use. The belt 18 is looped around the pulley l6, turnedthrough an angle corresponding to the roller 10 to which it is to beattached, and looped over its associated roller 10, Each roller 10 isprovided with a driven pulley which, in the illustrated embodiments,consists of a spoolshupcd section 17 of smaller diameter than itsadjoining roller portions. The spool-shaped section 17 may also consistof a groove or depression in the roller surface, but in either case itis necessarily of smaller diameter than its adjoining roller portions sothat the periphery of the drivebelt 18 does not protrude above the planeof the pass line.

It will be observed that the spool-shaped portion 17 of each of the liverollers 10 is located at a position along the length of the roller 10corresponding to the position of the drive shaft 12 beneath the curvedconveyor section. This is so that the individual drive pulleys 16carried by the drive shaft 12 are each disposed adjacent a correspondingpowered roller l0, allowing the use of belts 18 of uniform length foreach of the rollers 10 of the curved section.

Preferably, the drive pulleys 16 are constructed as shown in FIG. 5,with each pulley 16 being rotatably carried by the drive shaft 12 andslippable thereon to provide a friction drive. This allows the driveshaft 12 to continue rotating even if one or more of the live rollers 10should be halted for any reason. Furthermore, each drive pulley 16 ispreferably made axially shiftable along the drive shaft 12 in a mannerdescribed in our copending patent application Drive for RollerConveyors, Ser. No. 842,043 filed May 5, 1969. The latter feature allowseach drive pulley 16 to seek its optimum driving position along thedrive shaft 12 with respect to its associated roller 10.

As shown in the second exemplary embodiment of FIGS. 3 and 4, taperedlive rollers 20 may also be used. Each driven roller 20 is preferablytapered uniformly along its length, with decreasing diameter toward thecenter of conveyor curvature. In this waythe peripheral or linear speedof the roller surface varies with radius from the center of conveyorcurvature, so that a conveyed object is moved faster toward the outsideof the conveyor section than at the inside. This allows the object tomaintain its orientation upon passing through the curved conveyorsection, leaving the curved section in the same orientation relative toits direction of movement as when it entered. In this embodiment, thedriven pulleys again consist of spool-shaped sections 21 in the surfaceof their respective rollers 20, but it will be observed that thesections 21 are of different diameter, corresponding to their varyingpositions along the length of the tapered rollers 20. As a furtherfeature of the invention, the tapered rollers 20 are driven at aconstant rotational speed by providing drive pulleys 22 of varyingdiameter. The diameter of each drive pulley 22 varies in inverseproportion to the spool-shaped section 21 on the tapered roller 20 withwhich it is associated. For this reason rotation of the drive shaft 12by the motor 13 results in uniform rotational speed for each of thedriven tapered rollers 20.

It will be appreciated that the friction drive feature described inconnection with the embodiment of FIGS. 1 and 2 is also usefullyemployed in the embodiments of FIGS. 3 and 4. The drive pulleys 22 ofvarying diameter are also desirably made shiftable along the drive shaft12 in the same manner. In either of the illustrative embodiments, theslippable friction drive feature may also be incorporated by providing aseparate slippable pulley for each straight roller 10 or tapered roller20 in place of the spool-shaped sections 17, 21 as described. In thelatter case, thedrive pulleys I6, 22 may be fixed to the drive shaft 12since the frictional connection is provided in the rollers 10, 20instead of at the drive shaft 12.

The following is claimed as invention:

1. In a live roller conveyor, a plurality of angled rollers disposed ina common plane to define a curved pass line, a powered straight driveshaft, a friction clutch drive means interconnecting said straight driveshaft with certain of said rollers, said friction clutch drive meansincluding a driven pulley carried by each of said certain rollers and acorresponding drive pulley carried by the drive shaft adjacent each saiddriven pulley and a drivebelt looped between each of said adjacentpulleys.

2. Apparatus as defined in claim 1 in which said driven pulley has asmaller diameter than the adjoining roller portions, and one of eachsaid adjacent drive and driven pulleys is rotatably carried forslippable friction drive.

3. Apparatus as defined in claim 1 in which the rollers are taperedtoward the center of pass line curvature with the driven pulleys beingformed in the surface of the live rollers, and with the straight driveshaft intersecting the live rollers at points of varying roller diameterand driven pulley diameter,

and in which the diameter of the drive pulleys varies in inverseproportion to the diameter of the driven pulleys, whereby the rotationalspeed of each live roller is substantially the same.

4. Apparatus as defined in claim 1 in which each of said

1. In a live roller conveyor, a plurality of angled rollers disposed ina common plane to define a curved pass line, a powered straight driveshaft, a friction clutch drive means interconnecting said straight driveshaft with certain of said rollers, said friction clutch drive meansincluding a driven pulley carried by each of said certain rollers and acorresponding drive pulley carried by the drive shaft adjacent each saiddriven pulley and a drivebelt looped between each of said adjacentpulleys.
 2. Apparatus as defined in claim 1 in which said driven pulleyhas a smaller diameter than the adjoining roller portions, and one ofeach said adjacent drive and driven pulleys is rotatably carried forslippable friction drive.
 3. Apparatus as defined in claim 1 in whichthe rollers are tapered toward the center of pass line curvature withthe driven pulleys being formed in the surface of the live rollers, andwith the straight drive shaft intersecting the live rollers at points ofvarying roller diameter and driven pulley diameter, and in which thediameter of the drive pulleys varies in inverse proportion to thediameter of the driven pulleys, whereby the rotational speed of eachlive roller is substantially the same.
 4. Apparatus as defined in claim1 in which each of said driven pulleys is rotatably carried and axiallyshiftable on said drive shaft for slippable frictional drive, wherebyeach drive pulley may seek its position of optimum driving efficiency.